The present invention relates to a drive arrangement for a hybrid-drive motor vehicle.
In conventional hybrid drive arrangements employing an internal combustion engine as a first source of drive and an electrical machine as a second source of drive, the internal combustion engine acts on one axle differential (to give front-wheel or rear-wheel drive) or on two axle differentials (to give all-wheel drive), via a speed-change gearbox having gear ratios (six or seven for example) which cover the motor vehicle's speed range. The electrical machine is able to provide a drive output to one of the axle differentials either directly or by being coupled thereto via the gearbox. If the motor vehicle has a relatively wide speed range and this range is to be covered by an electrical machine whose weight is good (but whose torque is lower), then a further gearbox having two gear ratios for example is required at the electrical machine.
DE 10 2008 023 732 A1 for example shows a hybrid drive in which a first electrical machine is inserted between the internal combustion engine and the gearbox and a second electrical machine provides an output drive to the same axle differential as the internal combustion engine, via planetary gearing to allow speeds to be matched.
Further, WO 2011/014531 describes a hybrid drive arrangement in which a first electrical machine is coupled to the change-speed gearbox flange-mounted on the internal combustion engine and is able in addition to provide a drive output to one axle differential, while a second electrical machine is connected for drive directly to a second axle differential to provide all-wheel drive.
The electrical machines can be connected in the usual way to act as drive motors, to rotate freely or to act as generators in a recuperation mode.